The present invention relates to closure devices for carbonated beverage containers. The retention of the carbonation of a beverage after the container is initially open has been a problem recognized in the prior art. After the container is initially unsealed, the carbonated beverage immediately begins to loose its carbonation. Over time the beverage becomes flat even though the cap is utilized to reseal to the container. The carbonation continues to escape from the liquid into the interior of the container above the liquid.
A patent search was done and the following U.S. patent Nos. were found: U.S. Pat. No. 4,723,670 to Robinson et al which provides a hand-operated pump combined with a closure cap for sealing and pressuring the open space within a carbonated beverage container, U.S. Pat. No. 5,031,785 to Lemme which provides a combination pressure and vacuum pump for food or drink, and U.S. Pat. No. 4,899,896 to Metzger which provides a cap adapted for use in pressurizing the interior of a container for carbonated beverages.
The above mentioned patents disclose a device to re-pressurize the container to retain the carbonation within the beverage container once the container is opened. Additionally, the patents found from the search performed did not disclose a structure similar to the applicant's structure to be described herein.